Question

Answer 1

\(2,\)

\(y=\dfrac{x}{\left(x^2-1\right)\sqrt{x-1}}\)

Hàm số xác định \(\Leftrightarrow\left\{{}\begin{matrix}x^2-1\ne0\\\sqrt{x-1}\ne0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x\ne\pm1\\\sqrt{x-1}>0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x\ne\pm1\\x>1\end{matrix}\right.\)

\(\Rightarrow D=\left(1;\text{+∞}\right)\)

\(\Rightarrow\) Chọn đáp án \(B\)